Polarization and Electrocatalyst Selection for Polybenzimidazole Direct Methanol Fuel Cells

2013 ◽  
Vol 11 (3) ◽  
Author(s):  
Brenda L. García-Díaz ◽  
Héctor R. Colón-Mercado ◽  
Kevin Herrington ◽  
Elise B. Fox
Keyword(s):  
Fuel Cells ◽  
High Temperature ◽  
Methanol Oxidation ◽  
Direct Methanol Fuel Cells ◽  
Rotating Disk Electrode ◽  
Membrane Electrode ◽  
Power Sources ◽  
Membrane Conductivity ◽  
Direct Methanol ◽  
Methanol Fuel Cells

High temperature direct methanol fuel cells (DMFCs) using polybenzimidazole (PBI) membranes could improve the energy density of portable power sources. This study examines the polarization of vapor phase PBI DMFCs constructed with commercial membranes manufactured by a sol-gel method. The polarization of the high temperature DMFCs is compared to similar low temperature membrane electrode assemblies (MEAs) using Nafion® membranes. The results showed that the cathode of the PBI DMFC had higher kinetic losses that are likely due to phosphate poisoning of the Pt electrocatalyst. At the tested conditions, the membrane conductivity of the PBI MEAs was comparable to the Nafion® MEA even with no humidification. Higher cell temperatures significantly improved PBI DMFC performance for Pt electrocatalyst electrodes. In full cell tests, the PBI DMFC MEAs had higher performance than Nafion® MEAs with similar catalyst loadings. The Pt and PtRu catalysts were tested for methanol oxidation and oxygen reduction activity by a rotating disk electrode (RDE) under 0.5 M H2SO4 and 0.5 M H3PO4. The combination of the polarization and RDE results for the PBI and Nafion® DMFCs suggest that Pt is a more active electrocatalyst for methanol oxidation in PBI than in Nafion®.

Micro-Fluidic Assisted Passive Direct Methanol Fuel Cells

2012 ◽  
Author(s):  
Gladys Garza ◽  
Peiwen Li ◽  
Douglas Loy
Keyword(s):  
Fuel Cells ◽  
Direct Methanol Fuel Cells ◽  
Electrochemical Reaction ◽  
Cathode Side ◽  
Carbon Paper ◽  
Membrane Electrode ◽  
Operation Temperature ◽  
Direct Methanol ◽  
Methanol Fuel Cells ◽  
And Control

A novel design of micro-fluidic structure has been proposed to facilitate passive methanol supply and ventilation of carbon dioxide in direct methanol fuel cells (DMFC). Experimental study was conducted for three in-house fabricated cells which have different membrane-electrode-assemblies (MEA) and cathode-side air-breathing current collectors. Low rate of passive methanol supply and control was accomplished through capillary-force-driven mass transfer in the in-plane of carbon paper wicks. The low methanol supply rate using this passive method only meets the need of fuel of the electrochemical reaction, and there is almost no surplus methanol that could cross over the membrane. The micro-fluidic structure on the anode plate also makes passive removal of the CO2 gas from the electrochemical reaction. The influence of the concentration of methanol and cell operation temperature was examined and compared in the study. The results reveal very promising performance in the passive DMFCs when a methanol concentration is above 8M.

scholarly journals Methanol-Tolerant M–N–C Catalysts for Oxygen Reduction Reactions in Acidic Media and Their Application in Direct Methanol Fuel Cells

Catalysts ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 650 ◽  
Author(s):  
Carmelo Lo Vecchio ◽  
David Sebastián ◽  
María Lázaro ◽  
Antonino Aricò ◽  
Vincenzo Baglio
Keyword(s):  
Fuel Cells ◽  
Oxygen Reduction ◽  
Large Scale ◽  
High Efficiency ◽  
Direct Methanol Fuel Cells ◽  
Cell System ◽  
Rotating Disk Electrode ◽  
Capital Costs ◽  
Direct Methanol ◽  
Methanol Fuel Cells

Direct methanol fuel cells (DMFCs) are emerging technologies for the electrochemical conversion of the chemical energy of a fuel (methanol) directly into electrical energy, with a low environmental impact and high efficiency. Yet, before this technology can reach a large-scale diffusion, specific issues must be solved, in particular, the high cost of the cell components. In a direct methanol fuel cell system, high capital costs are mainly derived from the use of noble metal catalysts; therefore, the development of low-cost electro-catalysts, satisfying the target requirements of high performance and durability, represents an important challenge. The research is currently addressed to the development of metal–nitrogen–carbon (M–N–C) materials as cheap and sustainable catalysts for the oxygen reduction reaction (ORR) in an acid environment, for application in polymer electrolyte fuel cells fueled by hydrogen or alcohol. In particular, this mini-review summarizes the recent advancements achieved in DMFCs using M–N–C catalysts. The presented analysis is restricted to M–N–C catalysts mounted at the cathode of a DMFC or investigated in rotating disk electrode (RDE) configuration for the ORR in the presence of methanol in order to study alcohol tolerance. The main synthetic routes and characteristics of the catalysts are also presented.

Bimetallic alloy and semiconductor support synergistic interaction effects for superior electrochemical catalysis

Nanoscale ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 4719-4728 ◽  
Author(s):  
Yunshan Zheng ◽  
Yan Zhai ◽  
Maomao Tu ◽  
Xinhua Huang ◽  
Mingcong Shu ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Methanol Oxidation ◽  
Oxidation Reaction ◽  
Direct Methanol Fuel Cells ◽  
Methanol Oxidation Reaction ◽  
Electrochemical Catalysis ◽  
Anode Catalysts ◽  
Bimetallic Alloy ◽  
Direct Methanol ◽  
Methanol Fuel Cells

The design and fabrication of economically viable anode catalysts for the methanol oxidation reaction (MOR) have been challenging issues in direct methanol fuel cells (DMFCs) over the decades.

Improved Methanol Oxidation Activity Through Oxidation-Induced Phase Separation of PtRu Electrocatalysts

2000 ◽  
Vol 6 (S2) ◽  
pp. 24-25
Author(s):  
R.M. Stroud ◽  
J.W. Long ◽  
K.E. Swider ◽  
D.R. Rolison
Keyword(s):  
Fuel Cells ◽  
Methanol Oxidation ◽  
Direct Methanol Fuel Cells ◽  
Ruthenium Oxide ◽  
Hydrogen Fuel ◽  
Oxidation Activity ◽  
Power Sources ◽  
Bimetallic Alloys ◽  
Point Of Use ◽  
Direct Methanol

Direct methanol fuel cells (DMFCs) offer a simpler, safer technology for point-of-use power sources compared to other hydrogen fuel cells, by avoiding the need to store hydrogen fuel or to carry out the reformation of hydrocarbons. The direct methanol oxidation electrocatalyst of choice is a nanoscale black consisting of a 50:50 atom % mixture of Pt and Ru. It has recently become known that these presumed bimetallic alloys in fact contain an array of metal, oxide and hydrous phases, which are easily misidentified in routine x-ray diffraction measurements due to particle size-broadening and poor crystallinity. By combining transmission electron microscopy, electrochemistry and thermogravimetric studies, we demonstrate here that the route to improved catalytic activity is not by phase purification of the bimetallic alloys, but instead phase engineering of hydrous ruthenium oxide and Pt mixtures.

Pt–CoP/C as an alternative PtRu/C catalyst for direct methanol fuel cells

2016 ◽  
Vol 4 (47) ◽  
pp. 18607-18613 ◽  
Author(s):  
Jinfa Chang ◽  
Ligang Feng ◽  
Kun Jiang ◽  
Huaiguo Xue ◽  
Wen-Bin Cai ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Power Density ◽  
Methanol Oxidation ◽  
Direct Methanol Fuel Cells ◽  
Direct Methanol ◽  
Methanol Fuel Cells

A novel Pt–CoP/C electrocatalyst was developed for direct methanol fuel cells. This catalyst showed superior power density to commercial Pt/C and PtRu/C catalysts. In situ ATR-SEIRAS technology revealed that the presence of CoP in the Pt-based catalyst can promote the methanol oxidation to final CO2 products.

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